1. Field of the Invention
This invention relates to oil soluble dispersant additives useful in fuel and lubricating oil compositions, including concentrates containing said additives, and methods for their manufacture and use. The dispersant additives are dicarboxylic acids, anhydrides, esters, etc., substituted with a high molecular weight hydrocarbon group, and derivatives thereof such as salts, amides, imides, esters, oxazolines, etc. formed by further reaction with amine, alcohol, amino alcohols, and which may be further treated, e.g. borated. The high molecular weight hydrocarbon group has a number average molecular weight (M.sub.n) of about 1500 to 5000. The additives will have a ratio (functionality) of about 1.05 to 1.25 dicarboxylic acid producing moieties per said high molecular weight hydrocarbon used in the reaction.
2. Prior Disclosures
U.S. Pat. No. 4,234,435 discloses as oil additives, polyalkene substituted dicarboxylic acids derived from polyalkenes having a M.sub.n of 1300 to 5,000 and containing at least 1.3 dicarboxylic acid groups per polyalkene.
Canadian Patent 895,398 discloses reacting a mole of an unsaturated hydrocarbon group of 700 to 10,000 mol. wt. with 1 to 1.5 moles of chloro-substituted maleic or fumaric acid, which material can then be further reacted with alcohol.
U.S. Pat. No. 3,927,041 discloses a mole of polybutene of 300 to 3,000 mol. wt. containing 5 to 200 ppm 1,3 dibromo-5.5-dialkylhydantoin as a catalyst reacted with 0.8 to 5, generally 1.05 to 1.15 moles of dicarboxylic acid or anhydride, to form materials which can be used per se, or as esters, amides, imides, amidines, in petroleum products.
U.S. Pat. No. 3,215,707 discloses reacting chlorine with a mixture of polyolefin up to 50,000 molecular weight, especially of 250 to 3,000 molecular weight with one or more moles of maleic anhydride depending upon whether one or more succinic anhydride radicals are to be in each polymer molecule.
U.S. Pat. Nos. 4,113,639 and 4,116,876 disclose an example of alkenyl succinic anhydride having a molecular weight of the alkenyl group of 1300 and a Saponification Number of 103 (about 1.3 succinic anhydride units per hydrocarbon molecule. This alkenyl succinic anhydride may be reacted with polyamine and then boric acid (U.S. Pat. No. 4,113,639), or may be reacted with an amino alcohol to form an oxazoline (U.S. Pat. No. 4,116,876) which is then borated by reaction with boric acid.
U.S. Pat. No. 4,062,786 in Example 13 shows a polyisobutenylsuccinic anhydride of molecular weight of about 1300 and a Saponification Number of about 100 (about 1.25 succinic anhydride units per alkenyl group).
U.S. Pat. No. 4,123,373 in Example 3 shows a polyisobutenylsuccinic anhydride of about 1400 molecular weight having a Saponification Number of 80 (about 1.07 succinic anhydride units per polyisobutylene units.
Further related prior disclosures, which are expressly incorporated herein by reference in their entirety are U.S. Patents: U.S. Pat. Nos. 3,087,936; 3,131,150; 3,154,560; 3,172,892; 3,198,736; 3,219,666; 3,231,587; 3,235,484; 3,269,946; 3,272,743; 3,272,746; 3,278,550; 3,284,409; 3,284,410; 3,288,714; 3,403,102; 3,562,159; 3,576,743; 3,632,510; 3,836,470; 3,836,471; 3,838,050; 3,838,052; 3,879,308; 3,912,764; 3,927,041; Re. U.S. Pat. No. 26,330; U.S. Pat. Nos. 4,110,349; 4,113,639; 4,151,173; 4,195,976; and U.K. Patents 1,368,277 and 1,398,008.